1. Field of the Invention
This invention relates to the treatment of "ore" (i.e., any leachable material) for the purpose of extracting metals in general and more particularly to the exposure of ore to a leaching solution during a cyanidation metal extraction process.
2. Prior Art
Many metals, particularly precious metals are found in ore or mine dump tailing piles or in sewage treated at sewage plants and must be extracted from this material to be utilized. Conventional ore extraction processes are described in the "Handbook for Prospectors and Operators of Small Mines" by M. W. von Bernewitz, 4th Ed., McGraw Hill Book Company, Inc., pp 3407 et seq.
The most common methods of extracting precious metals, such as gold and silver, from ores are generally referred to as the cyanidization or leaching processes. These processes are carried out by up flow, down flow and percolation of the leaching solution through the ore.
A common disadvantage of these prior art methods is the occurrence of channeling within the fines of the ore over a period of time. As a result the extraction efficiency is reduced.
In order to reduce channeling, various mechanical agitators have been employed to dispense the ore throughout the leaching solution. Among these methods are paddles, movable tanks and flowing fluids such as water and leaching solutions. Each of these agitation methods fail to completely disperse the ore and each require expensive equipment which must be maintained such as pumps, motors, belts, etc.
Another disadvantage of prior art metal extraction processes, which utilize flowing leaching solutions, is the loss of leaching solution over a period of time due to evaporation and excessive aeration of the solution.